Distinct Location and Prevalence of α-, β-Catenins and γ-Catenin/Plakoglobin in Developing and Denervated Skeletal Muscle

Abstract

We studied the distribution of α-catenin, β-catenin and γ-catenin/plakoglobin in developing, adult and denervated mouse skeletal muscle. During primary myogenesis, all three catenins present a subsarcolemmal distribution within primary myotubes. During secondary myogenesis they accumulate at myotube-myotube contacts. In contrast to the other catenins, γ-catenin is strongly expressed in the sarcoplasm. In adult muscle, all three catenins are localized on the presynaptic elements of the neuromuscular junction. In denervated muscles, α-and β-cat-enins are upregulated like N-and M-cadherin, while the levels of γ-catenidplakoglobin remain unchanged. The developmental changes in localization and regulation of α-and β-catenins in muscle compared to γ-catenin/plakoglobin are suggestive of a privileged association of α-and β-catenins with N-and M-cadherins, while γ-catenin/plakoglobin appears to be expressed quite independently and must assume a different role during myogenesis.

Key Words:

• catenin
• cadherin
• skeletal muscle
• myogenesis
• development
• neuromuscular junction
• mouse development